View decoration role empty on Windows

**sebr** · 28th October 2007, 02:08

Hi,
I am trying to write a small cross platform application which shows an
icon view display of images. These images are loaded in a thread since
they are quite large. The loading thread simply sends a thumbnailed
QImage in a signal which is observed by my Model.

My subclass of QAbstractItemModel::data() returns QIcon( thumbnail )
for the DecorationRole to display the image on the View.

This works perfectly fine on Linux, but Windows shows no decoration,
simply the associated text returned by DisplayRole.

I suppose the real problem is that I don't have a windows build
environment, but I'm passing off the code to someone else to build.

Using Qt 4.3

**jpn** · 28th October 2007, 07:59

Which image format? Perhaps his Qt was built without support for such image format. Give PNG images a try..

**sebr** · 28th October 2007, 09:55

Bingo. PNG files are loaded without a problem. Thanks. I'll have to look into how to compile Qt with alternate image format support.

**sebr** · 28th October 2007, 09:58

Originally Posted by jpn

Which image format? Perhaps his Qt was built without support for such image format. Give PNG images a try..

Although it is strange since the QImage documentation explicitly has jpg image support out of the box.

What went wrong? Is this a windows specific thing?

**jpn** · 28th October 2007, 10:03

I think JPG support is compiled as a plugin by default. Try placing the "qjpeg4.dll" -plugin into an "imageformats" -subdirectory into the directory where the application is located in:

app\app.exe
app\imageformats\qjpeg4.dll